De Ford, Miriam Allen
Twayne Publishers, 1967
Buku Teks
Hendrick House, 1955
Buku Teks
Michaela D. Dwianto, author
Universitas Indonesia, 1988
UI - Skripsi (Membership)
Kuzminzkaya, Tatyana A., author
Macmillan, 1948
Buku Teks
Hands, Timothy
Macmillan, 1989
Buku Teks